Precautions

If you will be taking this medicine for a long time, it is very important that your doctor check you at regular visits for any problems or unwanted effects that may be caused by this medicine. Blood tests may also be needed to check for unwanted effects.

Using this medicine while you are pregnant can harm your unborn baby. Use an effective form of birth control to keep from getting pregnant. You should continue to use birth control at least 4 months after you have stopped taking this medicine. However, if you think you have become pregnant while using the medicine, tell your doctor right away.

Contact your doctor right away if you have any changes in your heart rhythm. You might feel dizzy, faint, or have a fast, pounding, or uneven heartbeat. Make sure your doctor knows if you or anyone in your family has ever had a heart rhythm problem such as QT prolongation.

Serious skin reactions can occur with this medicine. Check with your doctor right away if you have blistering, peeling, or loosening of the skin; red skin lesions; severe acne or skin rash; sores or ulcers on the skin; or fever or chills while you are using this medicine.

Avoid overexposing your skin to sunlight. Always use sunscreen or sun-blocking lotions and wear protective clothing and hats while you are using this medicine and for 4 months after the last dose.

Call your doctor right away if you have unexplained shortness of breath, cough, and fever that comes on suddenly. These may be symptoms of a serious lung condition.

Stop using this medicine and call your doctor right away if you have confusion; difficulty with speaking; slow speech; an inability to speak; an inability to move your arms, legs, or facial muscles; double vision; or a headache. These may be symptoms of a stroke.

This medicine may increase your chance of bleeding. Tell your doctor right away if you have bleeding gums, coughing up blood, difficulty in breathing or swallowing, dizziness, headache, increased menstrual flow or vaginal bleeding, nosebleeds, prolonged bleeding from cuts, red or dark brown urine, red or black, tarry stools, or shortness of breath. To help with this problem, stay away from rough sports or other situations where you could be bruised, cut, or injured. Brush and floss your teeth gently. Be careful when using sharp objects, including razors and fingernail clippers.

If you are rapidly gaining weight, having shortness of breath, chest pain or discomfort, extreme tiredness or weakness, irregular breathing, irregular heartbeat, or excessive swelling of the hands, wrist, ankles, or feet, check with your doctor immediately. These may be symptoms of heart problems or your body keeping too much water.

This medicine may cause diarrhea. This may also increase your risk of having an electrolyte imbalance (e.g., low potassium, magnesium, or calcium in the blood). Tell your doctor right away if you start having muscle cramps or twitching, mood or mental changes, or unusual tiredness or weakness while being treated with this medicine.

Check with your doctor if you have a headache, seizures, confusion, blurred vision or other visual problems. These may be symptoms of a rare and serious condition called reversible posterior leukoencephalopathy syndrome (RPLS).

Check with your doctor right away if blurred vision, difficulty with reading, eye pain or irritation, or any other vision change occurs during therapy. Your doctor may want you to have your eyes checked by an ophthalmologist (eye doctor).

This medicine may cause blurred vision. Make sure you know how you react to this medicine before you drive, use machines, or do anything else that could be dangerous if you are not alert or able to see well.

Do not take other medicines unless they have been discussed with your doctor. This includes prescription or nonprescription (over-the-counter [OTC]) medicines and herbal (St. John's wort) or vitamin supplements.